1. Field
A heat pump system is disclosed herein.
2. Background
Heat pump systems are systems in which a refrigerant cycle operates to perform cooling and/or heating functions. The refrigerant cycle may include a compressor that compresses a refrigerant, a condenser that condenses the compressed refrigerant, an expansion device that decompresses the condensed refrigerant, and an evaporator that evaporates the decompressed refrigerant.
The condenser and the evaporator may serve as heat-exchangers to heat-exchange the refrigerant with a predetermined fluid. The predetermined fluid may include air or water.
If water is used as the predetermined fluid, the heat exchanger used for the condenser and the evaporator may include a shell and tube heat exchanger. The shell and tube heat exchanger may include a shell in which a refrigerant may flow, and a plurality of tubes disposed within the shell to allow water to flow therethrough. While the refrigerant and the water are heat-exchanged within the shell, the refrigerant may be condensed or evaporated.
In general, the shell and tube heat exchanger may be used in a chiller system. A chiller may supply cool water into a cool water consumer's place. In the chiller, a refrigerant circulating into a refrigerating system and water circulating between the cool water consumer's place and the refrigerating system may be heat-exchanged to cool the water. The chiller may be large-scaled equipment and thus installed at large buildings.
FIG. 1 is a schematic diagram of a refrigerant cycle applied to a shell and tube heat exchanger according to related art. Referring to FIG. 1, a refrigerant system 1 according to the related art may be provided with a refrigerating cycle.
In more detail, the refrigerant system 1 may include a compressor 2 that compresses a refrigerant, a condenser 3, into which a high-temperature, high-pressure refrigerant compressed in the compressor 2 may be introduced, an expansion device 8 that decompresses the refrigerant, which has been condensed in the condenser 3, and an evaporator 10 that evaporates the refrigerant, which has been decompressed in the expansion device 8. The refrigerant system 1 may further include a suction tube 15 disposed at an inlet side of the compressor 2 to guide the refrigerant discharged from the evaporator 10 into the compressor 2, and a discharge tube 16 disposed at an outlet side of the compressor 2 to guide the refrigerant discharged from the compressor 2 into the condenser 3. An oil recovery tube 9 to guide oil existing within the evaporator 10 into a suction side of the compressor 2 may be disposed between the evaporator 10 and the compressor 2.
The condenser 3 and the evaporator 10 may be provided as a shell and tube heat exchanger so that the refrigerant and the water may be heat-exchanged with each other. In more detail, the condenser 3 may include a shell 3a that defines an outer appearance thereof, a refrigerant inflow 4 disposed on a first side of the shell 3a and through which the refrigerant compressed in the compressor 2 may be introduced, and a refrigerant discharge 5 disposed on a second side of the shell 3a and through which the refrigerant condensed in the condenser 3 may be discharged.
The refrigerant inflow 4 may be disposed on an upper portion of the shell 3a, and the refrigerant discharge 5 may be disposed on a lower portion of the shell 3a. Thus, when a high-temperature, high-pressure refrigerant gas is introduced into the refrigerant inflow 4, the refrigerant gas may be changed in phase into a liquid refrigerant having a high specific gravity while being heat-exchanged, and the liquid refrigerant may be easily discharged through the refrigerant discharge 5.
The condenser 3 may further include an inner passage 3b disposed within the shell 3a to guide a flow of the refrigerant. The inner passage 3b may include a plurality of tubes. The fluid may include water, for example.
The condenser 3 may include a condenser inflow passage 6 to introduce the fluid into the shell 3a, and a condenser discharge passage 7 to discharge the fluid, which has been heat-exchanged in the condenser 3 on a side thereof. The fluid introduced into the shell 3a through the condenser inflow passage 6 may be heat-exchanged with the refrigerant, that is, absorb heat while flowing into the inner passage 3b and then be discharged through the condenser discharge passage 7. With this process, the refrigerant may be condensed.
The evaporator 10 may include a shell 10a that defines an outer appearance thereof, a refrigerant inflow 11 disposed on a first side of the shell 10a and through which the refrigerant expanded in the expansion device 8 may be introduced, and a refrigerant discharge 12 disposed on a second side of the shell 10a and through which the refrigerant evaporated in the evaporator 10 may be discharged. The refrigerant discharge 12 may be connected to the suction tube 15.
The refrigerant inflow 11 may be disposed on a lower portion of the shell 10a, and the refrigerant discharge 12 may be disposed on an upper portion of the shell 10a. Thus, when a low-temperature, low-pressure, two-phase refrigerant is introduced into the refrigerant inflow 11, the two-phase refrigerant may be changed in phase into a gas refrigerant having a low specific gravity while being heat-exchanged, and then the gas refrigerant may flow upward and be easily discharged through the refrigerant discharge 12.
The evaporator 10 may further include an inner passage 10b disposed within the shell 10a to guide a flow of the fluid. The inner passage 10b may include a plurality of tubes. The fluid may include water, for example.
The evaporator 10 may include an evaporator inflow passage 13 to introduce the fluid into the shell 10a, and an evaporator discharge passage 14 to discharge the fluid, which has been heat-exchanged in the evaporator 10, on a side thereof. The fluid introduced into the shell 10a through the evaporator inflow passage 13 may be heat-exchanged with the refrigerant, that is, dissipate heat while flowing into the inner passage 10b and then be discharged through the evaporator discharging passage 14. With this process, the refrigerant may be evaporated.
As described above, when the shell and tube heat exchanger according to the related art is used as the condenser, the refrigerant inflow may be disposed on the upper portion of the shell, and the refrigerant discharge may be disposed on the lower portion of the shell. Also, when the shell and tube heat exchanger according to the related art is used as the evaporator, the refrigerant inflow disposed on the lower portion of the shell, and the refrigerant discharge may be disposed on the upper portion of the shell. As a result, there is a limitation in that it is difficult to switch one heat exchanger into the condenser and the evaporator.